1. Field of the Invention
The present invention is an environmentally friendly (“green”) invention and relates to the field of reclaiming hydrocarbons from multiple sources and processes and the processing of liquid or liquefiable biomatter to yield biodiesel. More specifically, it concerns a method and apparatus for both (1) reclaiming hydrocarbons created in the refining of crude oil, the treatment of water contaminated with oil such as from ship's bilge water, oil spills, waste motor oil, grease, paint thinner, gasoline, jet fuel, then converting them into diesel and heating oil fuels, and (2) obtaining biodiesel fuel from liquid or liquefiable biomatter such as tallow, algae, chicken fat, cooking oil and grease, palm oil, soy bean oil, etc.
2. Description of the Prior Art
It has for some time been an objective of industrialized society to conserve hydrocarbons and to reclaim waste hydrocarbons where possible. Environmental concerns and the increasing world demand for nonrenewable fuels such as oil have also driven innovation into such areas as conservation, including the reclaiming of waste hydrocarbons, and the avoidance of the dumping of environmentally damaging waste such as oily bilge water from oceangoing vessels. At the same time, the dependence of a major industrialized countries on imported oil has led to emphasis upon innovation in the development of renewable fuels such as biodiesel derived from biomass. These general prior art considerations lead to the subject matter of the present invention in multiple respects which be described under several subject headings as follows:
Refining of Crude Oil
It is estimated that between 17 and 20 percent of every barrel of refined crude oil is “residuum” or “residual” product coming off the bottom of distillation columns during the refining process in U.S. refineries. With average production of 17.6 million barrels per day over the last several years, an estimated 1.1 billion barrels (46 billion gallons) of residual/slop oils come out of U.S. refining operations annually.
The larger refineries are normally fully integrated with chemical plants, enabling the use of a full range of catalytic cracking, hydro processing, alkylation and thermal processes to optimize crude oil utilization. With their economies of scale, turning residual/slop oil into useful fuels and petroleum-based products solves logistical problems and generates significant income for large refineries.
The smaller refineries (less than 100,000 barrels per day production) that use distillation to separate gasoline fractions from crude oil usually do not have the same capabilities for re-refining their slop as the large refineries. Typically, processors and reclaimers partially clean this residual/slop oil by treating it with demulsifiers, removing water and filtering sediments. Removal of water and heavy sediments by settling and particulates by filtration are the processes most commonly used by reclaimers. The resulting product is a low-grade bunker fuel that requires several measures when in use to prevent pollution of the environment. A small percentage of this residual/slop oil is re-refined by third parties into recycled lubricants using vacuum distillation.
It is a feature of the apparatus and method of the present invention to reclaim this residual/slop oil from medium to small refineries by converting it to high value diesel and heating oil fuels. This has the advantage of decreasing the U.S. dependency on imported foreign oil by improving the yield of fuels streams from each barrel of crude refined in these operations.
Bilge Water
Ships, especially ocean going vessels, accumulate bilge water while at sea and in their cleaning when in port, which contain high concentrations of hydrocarbons. When bilge is removed from ships in port, the water must be transported from the ship to reprocessing facilities where centrifuges and filters are used to achieve a low grade bunker fuel that can be sold into the marketplace.
The expense involved in removal of bilge water from vessels has caused many shipping companies to risk dumping oil contaminated water at sea risking fines and sanctions rather than pay the ongoing cost for treatment of the bilge in port. According to recent studies, nearly a hundred million gallons of oil enter the oceans of the Earth as a result of shipping annually. These estimated amounts are probably very low as they rely on known instances of dumping of oil into the ocean to estimate the overall extent of the pollution.
It is another feature of the apparatus and method of the present invention to extract disposable hydrocarbons in bilge water in a fashion that requires limited transportation costs and higher economic return on the reclaimed fuel. The present invention provides distillation capabilities that convert these waste oils to #2 diesel and #5 heating fuel that are environmentally sound and scalable, provides economic incentives for the shipping companies to cease their dumping of bilge water at sea.
Environmental Services
It is estimated that 30 percent of oil spills occur as a result of illegal dumping or the accidental collision or grounding of vessels. The remaining 70 percent of spills occur during routine operations either offshore or at reception facilities within ports, harbors and refineries.
The toxicity of oil is significant. One gallon of oil can contaminate one million gallons of water. One quart of oil can create a two-acre oil slick. For this reason, the environmental regulatory statutes in many countries throughout the world, including the United States, require entities responsible for the introduction of oil into the ecosystem to remove the oil spills. Even relatively small oil spills must be cleaned up in the U.S. Containment and recovery equipment used to address these spills include a variety of booms, barriers, and skimmers, as well as natural and synthetic absorbent materials. Mechanical containment is used to capture and store the spilled oil until it can be disposed of properly, often in specially designed landfills.
It is another feature of the apparatus and method of the present invention to separate disposable hydrocarbons from water and other liquids using portability distillation technology that is easily transported to spill locations. This ability eliminates the need for intermediation using booms, barriers, skimmers and natural or synthetic absorbent material. It eliminates the requirement for specially designed landfills and allows the recovered hydrocarbons to be converted into marketable petrochemical products, specifically #2 diesel and #5 heating fuels.
Waste Motor Oil
Another source of hydrocarbon feedstock is waste motor oil.
Biodiesel
Ethanol made from corn requires as much energy to produce as the alleged benefits realized by its production, thus failing to reduce the U.S. dependency on foreign oil. Unlike ethanol, biodiesel provides numerous benefits in terms of energy savings and environmental safety. Biodiesel can be pumped through existing petrochemical pipeline and refueling infrastructure. Biodiesel powers existing diesel engines without modification to the engines or the fuel. As is the case with ethanol, biodiesel can be blended with standard diesel fuels. Biodiesel also is biodegradable and non-toxic, unlike petrochemicals.
However, current biodiesel distillation technology is complicated and requires additives—e.g., methanol and sulfuric acid—that create expense and certain environmental hazards. The price of methanol alone has made the cost of producing biodiesel difficult from a profitability standpoint. Furthermore, the fact that much biodiesel production relies on food crops such as corn further complicates its path to economic viability. Thus, biodiesel production to date has failed to make a meaningful impact on the U.S. dependency on foreign oil.
It is a further feature of the apparatus and method of the present invention to produce biodiesel fuel without the use of additives or catalysts and using liquid or liquefiable feedstocks that are either not derived from food crops or are discarded in any event (e.g., tallow, algae, chicken fat, cooking oil and grease, palm oil, soy bean oil, etc.). Such capability enhances the economic viability of biodiesel production providing a means to create an industry that does not require tax credits to sustain its profitability. Being able to effect such production with scalable, portable technology allows the biodiesel fuel to be produced near the source of the feedstock and/or near the distribution infrastructure required to deliver the fuel to the end user.
The present invention processes biomass such as tallow, algae, chicken fat, cooking oil and grease, palm oil, soy bean oil, etc. by setting the temperature points to the specifications of the desired fuel. For biodiesel, where the distillation curve is 335° F. to 665° F., the equipment is set for these temperatures, which results in the conversion of the feedstock to biodiesel fuel. Some hydrocarbon products have a water issue, e.g., tallow is 30-35 percent water. In such a case, the water is not separated from the feedstock at the beginning, which results in a heat loss, but this is the simplest way to control a single stream product. The invention accepts all these different feedstock components blended together, or as a single feedstock stream.
Experience with the inventive equipment has shown that regardless of whether the feedstock is waste motor oil, tank bottoms, or tallow, there is a 3 to 6 percent light gas factor that is used to provide fuel to a fume incinerator, that can be supplemented as needed with whatever in the process is available such as poor quality product, #5 heating oil, or even #2 diesel or biodiesel if necessary. Chemistry works in favor of the invention, because it is usually processing a heavy molecular chain to a light molecular chain. This results in expansion such that the invention produces more finished fuel in most cases than the quantity of feedstock at the start, despite using some of feedstock, the light ends, as fuel in the fume incinerator. Expansion is typically in the range of 3 to 10 percent.
Specific prior art in the patent field include the following references: Wansbrough et al., U.S. Pat. No. 5,885,444 (“the '444 patent”), for A Process for Converting Waste Motor Oil to Diesel Fuel and Carraway, U.S. Patent Application Publication No. 20070039249 for Process for Converting Tallow to Diesel Fuel (“the '249 application”). These references suffered a considerable number of real world problems when reduced to practice. Examples of these problems follow:
The first one was temperature spikes within the plant operating process and early stage heat requirements to reach the first process temperature level to remove water, and the disposal of same. Collectors of waste hydrocarbons (a source for feed stock) make no effort to separate the collections. A truck with a tank capacity of 2000 gallons can make 20+ stops mixing each stop with the next, then the collector will place this 2000 gallon mix with other mixes in a larger tank. Because the weight of the various hydrocarbons differ, they tend to separate and create layers with different distillation curves, oil, grease, paint thinner, gasoline, jet fuel, water, etc., the result created temperature spikes when processed which makes the plant difficult if not impossible to operate when managed by tightly controlled temperature points (+ or −5° F.) to produce a marketable product that has a specification distillation curve.
The present invention solves that problem by pre-heating and stirring the contents of the preparation tank. Pre-heating is accomplished by placing pipes in the bottom of the prep tank where retained heat is transferred/piped from the residuals and #5 fuel oil (industrial burner fuel), if any, after processing. The pre-heated feed stock is thinner to manage, and separation of hydrocarbons is avoided by stirring/mixing the tank at all times with motor driven prattles within the tank creating a constant blended product, thus avoiding temperature spikes.
The next problem was the above prior art references was with the oxidizer. The oxidizer in the '444 patent and '249 application was a design to try to resolve major odor problems such as found in a paper mill, but in this case based on the light ends. The oxidizer in the '444 and '249 references was very large with a steel tank that was filled with ceramic balls. The balls were brought to the desired temperature of 2000° F., but required a huge amount of outside fuel such as propane attempt to maintain the odor control temperature, but it was not successful. The system start-up required the use of propane with a cost up to $5000 to reach the required temperature and over 12 hours to accomplish operating levels. The '444 system when placed in operation was a costly failure. This was resolved in the present invention by replacing the oxidizer with a fume incinerator. The result is that now the fume incinerator has become is the key element to processing not only by providing the only heat source (hot air) because it produces enough heat to power the entire apparatus and method, but it is a complete solution to eliminating harmful emissions and provides complete odor control.
In the present invention the fume incinerator mixes fuel with massive amounts of air, bring that air to 2000° F.+ while at the same time within the chamber being able to dispose of water and light end hydrocarbons that were the odor source with the prior art. The light ends are destroyed by the fume incinerator, while at the same time using the light ends as fuel to heat the air and power the entire apparatus. That is, the plant is fired by light ends (plus sometimes other fuels such as #5 heating oil when necessary) produced by the process and the chamber temperature of 2000° F. can be accomplished in 30 minutes. Thus the apparatus and method require no external fuel source (after start up) and operates by producing their own fuel, even from such dilute sources as bilge water. This is a huge improvement over the prior art.
An additional problem with the above described prior art concerned the distillation column. The distillation column in the '444 patent and '249 application used nutter rings dumped in the column or random packing. As a result, the plant experienced fouling, channeling, and required high reflux ratios. The present invention solves those problems with a multi-design with trays in the lower section where fouling is more prevalent and structured packing in the upper section where lighter material exists with a distributor between the two that re-distributes the liquid improves hydraulics leading to minimzed channeling and lower reflux demands. This increases production.
The next problem in the prior art references was overheating of high temperature pumps. Operation of the plant 24/7 created stress on the seals and bearings of high temperature pumps, failure of which forced the plant offline. To avoid failure at temperatures in the range of 750° F.+ and the ability to tolerate 1000° F., in the present invention, the seals and bearings are cooled by using heat transfer oil with the transfer oil cooled quickly and recirculated back through the seals and bearings by using a condenser to disburse heat with air cooling.
The present invention includes an energy conservation design absent from the '444 patent and '249 application. Retained heat from the residuals and finished #5 heating oil is used to preheat the feed stock by circulating some of residuals and #5 heating oil thus reducing the heat load on and fuel consumption by the fume incinertor. Light ends represent an emission odor problem, but are incinerated fully in the fume incinerator to provide heat for the process, supplemented as necessary with finished #5 fuel oil. The present invention is designed to consume, incinerate and destroy those elements within the process that are either harmful to the environment or would otherwise be sent to a landfill, that have no market value. The feed stock provides the process fuel required for the system and waste hydrocarbons such as light ends are used as fuel to power the fume incinerator to provide the required process heat as hot air. In addition, the finished fuel can be used to power an onsite generator to provide all electrical power required. Simply put, the present invention fuels itself, and that is hugely different than the prior art, which consumed enormous amounts of propane and did not solve the odor and emissions problems either.